Composition, process for making and process for treating cellulosic fabric



United States Patent Office Patented Dec. 4, 1962 2 3,067,062 CQMPQSKTHON, PRCHCESS FOR MAKING AND PRUCESS 13GB TREATENG CELLULOSIC FAEREC Gastao Etzel, Coliingswood, N.J., assignor to E. I. du

Pont de Nernours and Company, Wilmington, Del., a

corporation of il elaware No Drawing. Filed Apr. 5, 1961, Ser. No. 100,790

4 Claims. (Cl. 117143) This invention is directed to a novel composition usei ful as a dimensional stabilizer for cellulosic fabrics and more particularly to a composition consisting of 5,5- hexamethylenebis[tetrahydro-1,3 dimethylol -s-triazin- 2(1H)-one], hereinafter referred to as the hexamethylenebis(triazone), and tetramethylolurea. The present invention also relates to a process for manufacturing said composition and to a process for the application of this composition to cellulosic fibers.

Triazone resins have been used as dimensional stabilizers for cellulosic fabrics. These stabilizers, however, are deficient in one or more respects; for example, they may discolor the fabric during or after application, making it yellow; they may impart poor crease resistance; or, they may develop amine or fish-like odors. T etramethylolurea is also known as a fabric dimensional stabilizer, but it has the disadvantage of retaining chlotime from hypochlorite laundry bleaches. Fabric treated with it is, therefore, adversely affected in its tensile strength properties by ironing which releases the chlorine as hydrochloric acid. It would be highly desirable to provide a dimensional stabilizer for fabrics which does not possess any of the undesirable properties of the stabilizers which have been previously used.

It is, therefore, an object of this invention to provide a novel stabilizing composition. A further object is to provide such a novel composition consisting of 5,5- hexamethylenebis[tetrahydro-1,3 dimethylol-s -triazin- 2(1H)-one] and tetramethylolurea, which composition is particularly useful as a dimensional stabilizer for cellulosic fibers. A still further object is to provide a novel method for preparing a composition having significant utility as a dimensional stabilizer for cellulosic fabrics. Still another object is to provide an improved cellulosic fabric and a process for obtaining this improved cellulosic fabric by utilizing the novel stabilizer composition of the invention.

These and other objects will become apparent in the following description and claims.

More specifically, the present invention is directed to a composition consisting essentially of an aqueous solu tion containing from about to about 70% by weight of an active ingredient, said active ingredient con- L weight ratio of triazone to urea of between 1:0.4 and This invention also relates to a process for the manufacture of the heretofore described composition, in which process 1,6-hexanediamine is heated at 75 to 105 C. for one to four hours, at a pH between 8.5 and 10.0, with an aqueous solution containing to 85% by weight of a polymethylolurea consisting essentially of tetramethylolurea, the 1,6-hexanediamine being taken in an amount which is between .04 and .34 mole per mole of tetramethylolurea, followed by adjusting the concentration of the reaction mass with water to between 30% and 70% by weight; the reaction mass consisting of a mixture in aqueous solution of tetramethylolurea and 5,5-hexamethylenebis[tetrahydro- 1,3 dimethylol s-triazin-Z 1H) -one] The present invention includes a process for treating a cellulosic fabric with a composition consisting of 5,5-hexamethylenebis[tetrahydro-1,3 dimethylol-s-triazin-2(1H)-one] and tetramethylolurea in a weight ratio of between 1:04 and 1:10 which comprises padding the cellulosic fabric to pick up on the weight of the fabric between 3% and 10% of the composition together with between 0.5% and 2% of zinc nitrate catalyst, drying the treated fabric and heating it at a temperature above 300 F. (preferably at 325 to 350), neutralizing the resultant fabric with alkali followed by rinsing so that the fabric-rinsing solution equilibrium pH is between 7 and 7.5, and finally drying the fabric.

Another embodiment of this invention is the treated cellulosic fabric obtained by the novel process heretofore set forth.

PREPARATION OF THE COMPOSITION A logical process for preparing the invention composition is to prepare the hexarnethylenebis(triazone) and the tetramethylolurea separately and mix them in the proper proportions. While such a procedure is possible, the isolation of essentially pure 5,5'-hexmethylene-bis [tetrahydro-l,3 dimethylol-s-triazin 2(lH)-one] is troublesome and uneconomical. Also such a procedure requires at least two reaction vessels with the associated hold tanks and other attendant equipment. When just the molar quantities of 1,6'hexanediamine (1 mole) and tetramethylolurea (2. moles) to form the theoretical hexamethylenebis(triazone) are reacted only a partial conversion of the 1,6-hexanediamine occurs, and the product consists of the desired hexamethylenebis(triazone) mixed with tetramethylolurea and contaminated with unreacted diamine.

It has now been discovered that the diamine reactant is completely converted to the hexamethylene-bis(triazone) in'the presence of a substanital excess of tetramethylolurea, and the dimensional stabilizer may he satisfactorily manufactured by a procedure wherein a single reaction kettle is utilized. The single step process is more convenient and more economical than processes heretofore available.

The essential feature of the present novel process is that 1,6-hexanediamine is reacted with a polymethylolurea which is essentially tetramethylolurea, and the reaction is carried out with an excess of the polymthylolurea so that after the reaction is complete there remains in the product mixture both the hexamethylene-bis(triazone) reaction product and unreacted tetramethylolurea. This mixture is then adjusted to a concentration of active ingredients which makes it a product of commerce ready for sale to the textile industry. The reaction is represented by the following equation.

By a polymethylolurea which consists essentially of tetramethylolurea is meant the reaction product obtm'ned by heating an aqueous solution containing 4.1 moles of formaldehyde and 1 mole of urea at pH between 9 and 11.5 at to C. for 30 minutes. Such a product may be used directly for reaction with 1,6-hexanediamine. The polymethylolurea may also be obtained as a commercial product consisting of 74% polymethylolurea which is essentially tetramethylolurea, 20% formaldehyde, and 6% water. Just before this commercial product is used it is diluted wtih water to a concentra mixture under alkaline conditions as described above. The additional tetramethylolurea formed by this reaction of the added urea brings the concentration of the total tetramethylol in the solution to between 40% and about 85% by weight.

The reaction between 1,6-hexanediamine and the polymethylolurea is carried out between 75 and 105 C. for about 1 to 4 hours, the pH being controlled between 8.5 and 10.0 and the concentration of the polymethylolurea in solution being between 40% and 85% by weight. At temperatures appreciably lower than 75 C. the 1,6-hexanediamine tends to separate from the reaction mass, and the reaction rate is impractically slow. At temperatures above 105 C. some decomposition of the hexarnethylenebis(triazone) reaction product occurs and a pressure reaction vessel is required; it is preferred to operate the process at atmospheric pressure in open equipment. At a pH of the reaction medium much below 8.5 a product different from the desired hexamethylenebis(triazone) may be obtained. The process could be operated at a pH between 10 and 12, but there is no apparent advantage in a pH over 10, so this pH value is the preferred upper limit. The pH is obtained by adding a sodium hydroxide solution to the solution of the polymethylolurea.

The amount of 1,6-hexanediamine taken to react with the polymethylolurea according to this invention is between 004 and 0.34 mole per mole of polymethylolurea computed as tetramethylolurea. Thus, the polymethylolurea will be in excess and a portion of it will remain in the reaction product mixture as an essential ingredient of the fabric stabilizer. When 0.04 mole of the diamine per mole of tetramethylolurea is taken for the reaction the product contains the hexamethylenebis(triazone) and unreacted tetramethylurea in a ratio by weight of 1:10, and when 0.34 mole of the diamine per mole of the urea is taken this ratio becomes 1:0.4.

After the reaction is completed, the concentration of the reaction mixture is adjusted by adding or removing Water so that the active ingredients (that is, the sum of the hexamethylenebis(triazone) and tetramethylolurea) will be between 30% and 70% by weight. If water is to be removed, it is best done by distillation at reduced pressure to prevent any further reaction. The final product concentration for a given reaction mixture is conveniently attained by adjusting the specific gravity of the solution, after the relation between concentration and specific gravity has once been determined. The concentrated solution of the product is clear, stable to storage, and ready for use upon dilution with water to produce a fabric treating bath.

APPLICATION TO FABRICS The concentrated 30% to 70% solution of the product as manufactured is diluted to between 3% and 10% by weight and to this dilute solution is added between 0.5% and 2% by weight of zinc nitrate catalyst to provide a pad bath for the treatment of a cellulosic fabric. By a cellulosic fabric is meant a member of the group of the Well-known textiles of cellulose which includes cotton, rayon, linen, hemp, burlap, and the like. The fabric is treated with the pad bath containing the hexamethylenebis (triazone), tetramethylolurea, and zinc nitrate to apply from 3% to 10% of the fabric weight of the triazone-urea mixture and from 0.5 to 2% of zinc nitrate. The concentration of the pad bath will depend upon the pickup to be obtained and the amount of active ingredient mixture to be put on the fabric. When a 100% weight pickup is to be attained, i.e. the fabric is to pick up its own weight of solution, for example, the pad bath will contain between 3% and 10% of the triazone-urea mixture. Cotton Will usually be treated with between 3% and 5% by Weight of the active ingredient mixture on the fabric, whereas rayon fabric will be treated with 5% to of its weight of the active ingredient mixture. At the same time the fabric will pick up from 0.5% to 2 of its weight of zinc nitrate.

After the padding operation the fabric is dried and cured. Curing consists of heating the dry, treated fabric preferably at 300 to 350 F. for about 50 seconds to 180 seconds. Higher curing temperatures and longer curing times may be employed provided the tensile strength of the fabric is not too adversely affected.

After curing, the fabric should be washed in an alkaline solution to remove any unreacted active ingredient mixture and zinc nitrate and then rinsed to obtain the highest resistance to chlorine retention damage. If this is not done, the beneficial effects of chlorine resistance obtained by the process of this invention are not achieved. The washing operation may be done in a sodium carbonate solution of 0.1% to 1.0% by weight at to F. at a solution pH of 9 to 11. Other alkaline solutions which may be used include sodium bicarbonate, potassium carbonate, sodium hydroxide, borax, sodium phosphate, and the like. The rinsing step is carried out until the fabric-solution equilibrium pl-l is 7 to 7.5. The rinsing step is then followed by a final drying step employing any conventional means. The cellulosic fabric so treated is found to have remarkable properties of tensile strength, crease recovery, whiteness (reflectance) and resistance to the adverse effects of chlorine retention after bleaching nd ironing.

Representative examples illustrating the present inven tion follow.

PREPARATTON OF THE ACTIVE INGREDIENT MIXTURE The parts of the reactants and of water are parts by Weight.

Example 1 To 729 parts of urea-formaldehyde condensate containing 540 parts of tetramethylolurea, 146 parts of formaldehyde and 43 parts of Water are added 240 parts of water and 49 parts of urea. The pH of the solution is raised to pH 11 with 20% sodium hydroxide solution and the solution heated at 85 to 90 C. for 20 minutes to react the urea with 98 parts of the formaldehyde and form 147 parts of tetramethylolurea. The pH of thesolution is then reduced to pH 9.7 with acetic acid, and while still maintaining the temperature at 85 to 90 C. 42.5 parts of an 85% water solution of 1,6-hexanediamineis added over a period of /2 to 1 hour. The reaction mass is refluxed for 1 hour (102105 C.) and then heated for 1 hour at 85 to 90 C. The resultant solution is cooled! and its specific gravity reduced to 1.160 at 25 C. by the. addition of water. The solution is now treated with 21 parts of absorbent carbon black, stirred, and filtered. The: product consists of 1400- parts of an aqueous solution con-- taining about 35 parts of formaldehyde and 700 parts or 50% of active ingredient mixture which is 18% 5,5"-hexamethylenebis[tetrahydro l,B-dimethylol-s-triazin 2(lH)-- one] and 82% of a polymethylolurea consisting essen-- tially of tetramethylolurea.

The amounts and the molar ratio of the reactants and the concentration and composition of the active ingredient product of this example and of other examples of the invention process operated essentially as Example 1 are;

given 1n Table I WhlCh follows.

TABLE I(A) Tetramethylolurea (TMU) Parts 1,6-

hexane Molar ratio, Example Canon. in diamine HMDzTMU' Total starting (HMD) parts soln.,

percent by weight TABLE 1(3) Active ingredient Parts Concn. in Composition, percent Example product product by weight so 11. percentby weight Bis (tria- TMU zone) Example 6 Three pad baths were prepared as follows:

A B G Tetramcthyiolurea 4 O 3. 5 5,5-liexarnetllylenebis[tetrahydro-1,3-dimethylol-striazin-2(1H)one] 4 0. 7 Zinc nitrate O. 8 0.8 0.8 Water 95. 2 95. 2 05. 2

Each of the above pad baths was used totreat a fabric of bleached cotton sheeting. The fabric was padded to a 100% wet pickup, dried, and cured at 325 F. for 75 seconds. A portion of each of the treated fabric samples was then neutralized by washing in a water solution containing 0.2% by Weight of sodium carbonate and 0.05% of dodecyl sodium sulfate and rinsed until the equilibrium pH of the fabric-rinsing solution was 7.0. The fabric was dried and tested for tensile strength, crease recovery, whiteness, and damage from ironing after chlorine bleaching. The test results are:

Fabric treated in the pad bath A B O Tensile strength (lbs. per inch) 34 42 39 Crease recovery angle (degrees) (AATCC-tcnt.

test method 66-1959) 251 222 237 Whitcness (percent re ectance at 400 m (MgO used as standard) 85 83 84 Damage due to chlorine after boil washes (percent) (AATGCtent. test method 92-1958) 25 5 10 dehyde and alkaline fabric, the treated fabric was free from odor. No objectionable fish-like odor could be detected.

It is understood that the preceding examples are representative and that said examples may be varied, within the scope of the present total specification as understood by one skilled in the art, to achieve essentially the same results.

As many apaprently widely different embodiments of this invention may be made Without departing from the spirit and scope thereof, it is to be understood that this invention is not limited to the specific embodiments thereof except as defined in the appended claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A composition consisting essentially of an aqueous solution containing from about 30% to about by weight of an active ingredient, said active ingredient consisting of 5,5-hexarnethylenebis[tetrahydro-1,3-dimethylo1-s-triazin-2(lH)-one] and tetrarnethylolurea in a Weight ratio of triazone to urea of between 1:0.4 and 1: l0.

2. A process for manufacturing an aqueous solution containing from about 30% to about 70% by weight of an active ingredient, said active ingredient consisting of 5,5 -hexamethylenebis[tetrahydro-1,3-din1ethylol s triazin-2(1H)-one] and tetramethylolurea in a weight ratio of triazone to urea of between 1:0.4 and 1:10, said process being one wherein 1,6-hexanediamine is heated at C. to 105 C. for one to four hours, at a pH between 8.5 and 10.0, with an aqueous solution containing 40% to by weight of a polymethylolurea consisting essentially of tetramethylolurea, the 1,6-hexanediamine being utilized in an amount which is between .04 and .34 mole per mole of tetramethylolurea, followed by adjusting the concentration of the reaction mass with water to between 30% and 70% by weight; the reaction mass consisting of a mixture in aqueous solution of tetramethylolurea and 5,5'-hexamethylenebis[tetrahydro-1,3 dimethylol-s-triazin-2(1H)-one].

3. A process for treating a cellulosic fabric with a composition consisting of 5,5-hexamethylenebisItetrahydro- 1,3-dimethylol-s-triazin-2( 1H) -one] and tetramethylolurea in a weight ratio of between 1:0.4 and 1:10, which process comprises padding the cellulosic fabric to pick up, on the weight of the fabric, between 3% and 10% of the composition together with between 0.5% and 2% of zinc nitrate catalyst, drying the treated fabric and heating it at a temperature above 300 F., neutralizing the resultant fabric With alkali followed by rinsing so that the fabric-rinsing solution equilibrium pH is between 7 and 7.5, and finally drying the fabric.

4. A treated cellulosic fabric obtained according to the process of claim 3.

No references cited. 

3. A PROCESS FOR TREATING A CELLULOSIC FABRIC WITH A COMPOSITION CONSISTING OF 5,5''-HEXAMETHYLENEBIS(TETRAHYDRO1,3-DIMETHYLOL-S-TRIAZIN-2(IH)-ONE ) AND TETRAMETHYLOLUREA IN A WEIGHT RATIO OF BETWEEN 1:0.4 AND 1:10, WHICH PROCESS COMPRISES PADDING THE CELLULOSIC FABRIC TO PICK UP, ON THE WEIGHT OF THE FABRIC, BETWEEN 3% AND 10% OF THE COMPOSITION TOGETHER WITH BETWEEN 0.5% AND 2% OF ZINC NITRATE CATALYST, DRYING THE TREATED FABRIC AND HEATING IT AT A TEMPERATURE ABOVE 300*F., NEUTRALIZING THE RESULTANT FABRIC WITH ALKALI FOLLOWED BY RINSING SO THAT THE FABRIC-RINSING SOLUTION EQUILIBRIUM PH IS BETWEEN 7 AND 7.5, AND FINALLY DRYING THE FABRIC. 